Almost 50 percent of acute otitis media (AOM) episodes among children are caused by Streptococcus pneumoniae. Nasopharyngeal presence of S. pneumoniae increases the incidence of AOM and organism resistance to penicillin. Prevention of AOM with vaccines is becoming imperative as antibiotic treatment becomes less effective. The 23-valent pneumococcal polysaccharide vaccines offer variable response in children younger than two years and are ineffective in preventing pneumococcal AOM. More recently developed pneumococcal conjugate vaccines that cover seven to 13 serotypes cause a T-cell–dependent response and provide effective protection in children younger than two years. The available form is the 7-valent vaccine (Prevnar); it is approved for use in the United States in children younger than two years and can be used in children up to age nine. Jacobs reviewed treatment options and looked at the utility of vaccines in preventing AOM.
Treatment of AOM is usually empiric, because recovery of middle ear fluid for organism identification requires an invasive procedure. The recommended initial drug is oral amoxicillin, at the standard dosage (40 to 45 mg per kg per day) or high dosage (80 to 90 mg per kg per day) if the likelihood of resistant organism colonization is high. Tympanocentesis for fluid culture and drainage is recommended when treatment fails. Second-line empiric therapy includes high-dosage oral amoxicillin/clavulanate potassium, oral cefuroxime axetil, and intramuscular ceftriax-one (see the accompanying table). Insertion of a tympanostomy tube is useful for drainage but probably should not be used prophylactically because of evidence that early tube placement might not improve ultimate outcomes, such as speech and language development.
Because of the rise in pneumococcal resistance, control of AOM is moving from treatment to prevention. The currently licensed pneumococcal conjugate vaccine includes four of the six serotypes that most commonly cause AOM, as well as those that are most commonly antibiotic-resistant. Efficacy rates after vaccination are high, with significant reduction of S. pneumoniae isolation from middle ear drainage, a decrease in infectious episodes caused by covered serotypes, and a decrease in office visits. Current recommendations by the Centers for Disease Control and Prevention (CDC) include vaccination of all infants two to 23 months of age and of children up to 59 months of age who are susceptible to infection because of chronic illness or immunologic compromise.
The author concludes that conjugate pneumococcal vaccination significantly reduces the incidence of serotype-specific pneumococcal AOM. Long-term follow-up is needed to determine the clinical impact of pneumococcal serotype replacement. The CDC-advised treatment regimens for drug-resistant S. pneumoniae probably should be followed in children with AOM who have been vaccinated.